Gear shaping machine



Dec. 5,v 1944. G. G.`FREDER|CHS GEAR SHAPING MACHINE Filed May 8, 1941 3 Sheets-Sheet l Dec- 5, 1944- G. G. FREDx-:Rlcl-ls 2,364,065

GEAR SHAPING MACHI 5 Sheets-Sheet 3 C,

Filed May 8, 1941 PatentedDec. 5, 1944 GEAR SHAPING MACHINE Georg Gert FrederichsKassel-Brasselsberg, Germany; vested in" the Alien Property Custodian Application May 8,1941, Serial No. 392,532 In Germany December 12, 1939 2 Claims.

My inventionrelates to machines for shaping gears 'by the conjoint relative reciprocation and rotation of the workpiece and the tool, in which machines the tool -is on its return stroke disengaged from the work piece.

In the known machines of the said class either the tool spindle together with the cutter and the spindle' carrier or the Whole work supporting table together with the work piece must be withdrawn, and by the short and rapid movements of the heavy spindle carrier or of the supporting table the machinery is subjected to violent shocks which have an unfavourable influence on the cleanliness andexactness of the work. Moreover bulky driving vmeans are necessary for the said movements, which means are highly subjected to wear and require much power.. It is especially 4diil'lcult to ilx the heavy supporting table at-each shaping stroke.

The object of my invention is izo-eliminate the said drawbacks by disengaging the tool from the work piece in such a Way that the cutter is moved relatively to the'tool spindle, or that the tool spindletogether with the cutter is moved relatively to-the rvspindle carrier. By this arrangement it is rendered possible to use two cutting tools, of which the' `one performs the roughcutting, whereas the other performs the smoothing. In this way'a greater cleanliness and exactness of the toothed work and a longer duration of the cutting edges of the tools are attained.

Other objects of my invention will be apparent from the following speclilcation referring to the drawings. According to apreferred embodiment of my invention the movement of the cutter relatively to the tool spindle is executed with hydraulic means, and an object of my invention is also the exactadjustment of the tool relatively to the work piece.

VIn the drawings several embodiments of my invention are shown.

Fig. 1 is'a side elevation of the gear shaping machine, partly in section.

Fig. 11l is a side elevation of a shaping machine with two spindles, partly in section..

Fig. 12 is a front view of the machine according to Fig. 11,-part1y in section.

Fig. 13 is anY enlarged section of the two tool spindles, partly in section, arranged side by side.

Fig. 14 is a section according to the line XIV` XIV of Fig. 13.

Fig. 15 is also a section according to the line vXIV-XIV of Fig. 13 showing the adjustment of the working parts of the machinery relatively to a work piece of large diameter.

The work piece I is framed on the table Z which is rigidly connected with the spindle carrier 3 in which the tool spindle 4 is guided in vertical and axial direction. The tool spindle has several annular rack-teeth meshing with a toothed sector 1 which is rotatable about the axis B. By a rotation of the said sector the tool spindle is forced upwards or downwards in a vertical direction. Simultaneously the work piece I as well as the tool spindle 4 is rotated. The rotation or the tool. spindle is executed by means of the worm 8 and the worm wheel 9. The cutter 20 is articulated Fig. 7 shows anl embodiment according to which the cutter is moved relatively to the tool spindle to the tool spindle 4.

In the embodiments according to Figs. 2 and 3 D a bolt I2 and a piston I3 connected with vit is centrically arranged in the spindle 4. The said piston has tight fit in a cylindricbore I4, I1 of the spindle and operates like a hydraulic pressurepiston. The pressure liquid is fed with lthe necessary pressure through the inlet channels I5 and IB to the chambers I4 and I1.

The tool spindle is subjected to a reciprocal movement and is provided with a spur cogging I8 meshing with a corresponding cogging of the disc I9 to which the cutter 20 is fastened.

The disc I 9 has a convex spherical face 2i which ts into a corresponding spherical concavity 22 of the bolt I2. On the other side a nut 23 is(screwed upon the-bolt I2.

The disc I9 has an annular recess; of semicircular cross-section into which the lower end of hinge 25 flts. The said hinge is attached to a ring 2E set in a groove surrounding the tool spindle 4.

The ring 26 is held against rotation by the ears 21 engaging the rod 28. Correspondingly hinge 25 and the ring 26 remain stationary during the rotation of the tool spindle 4. The hinge 25 is arranged opposite to the cutting teeth of the cutter which are cleared away'from the 'tool spindle only on that side on which thecutting teeth engage the working piece. The cutter ls swung downwards by a vertical downward movement of .the bolt I2.

The operation of the machine is the following: At the beginning of the vertical working or cutting stroke of the tool spindle 4 the bolt I2 moves upward. Under. the influence of corresponding controlling means the pressure liquid is then fed to the lower chamber I'I of the cylinder to force the piston I3 of the bolt I2'upwards. The disc I9 and the cutter are pressed into the spur cogging I8 of the toolspindle 4, so that-the said disc I9 is rigidly connected with the tool spindle 4. The purpose of the corresponding spur coggings of the disc I9 and of the tool spindle 4 is (l) that they produce at each cutting or working stroke a rigid connection between the tool spindle 4 and the cutter 20 with the aid of the bolt I2 and (2) that they provide after each stroke for lan exact central position of the cutter relatively to the tool spindle.

After the end of the working stroke the pres-y sure liquid is fed through the channel I5 into the upper space I4 of the cylinder, and the bolt I2 is correspondingly pressed downwards, whereupon .the disc' I9 and the cutting gear 29 are on one side cleared away from the tool spindle 4, so that those teeth of the cutter 20 which made the cut in the work piece I on the down stroke of spindle 4 are separated such a distance from the work piece I that on the return stroke of the tool spindle and of the cutter 20 the cutting edges of the latter freely pass the work piece I without touching the' same.

The way along which the oscillatory movement of the cutter 29 about the hinge 25 or the pivot 30 of the hinge 25 takes place must not be more than a few millimeters. In Fig. 2 the line 3| corresponds with the working position of the cutting edge, and the line 32 corresponds with the position according to which the cutting edge is cleared away from the work piece.

According to the modification shown in Figs. 4, 5 and 6 the tool is not tilted downwards on only one side but retains its horizontal position during its movements relatively to the tool spindle. Also here the tool spindle 4 has a spur cogging I8 which is engaged by a corresponding countercogging of the disc I9 for the cutter 20. Inside ofthe spindle 4 a. socket member 33 is rotatable.

. The said socket member 33 has an eccentric bore in which a bolt 34 is rotatable and axially displaceable. The said bolt 34 is threaded at 35 and has an eccentrically arranged cylindrical stud 36 which is concentric to the spindle 4 and which engages with a concentric bore of the disc I9. The disc is held on the stud at one end of the same by the annular shoulder 31 and at the other The channels. 43, 44, 45 and 46 form the inlets t0 the pressure chambers 4I, 42.

The socket member 33 has a central pivot 4l which protrudes through a corresponding bore of the tool spindle 4 to the outside. To the said pivot a lever 48 is keyed which holds the socket during the operation in such a way that the tool spindle 4 is rotatable about. the socket member 33. In this Way the device for radially displacing the cutter remains immovable.

The operation is as following: At the end of the down cutting stroke, spindle 4 is rotated to bring channel 48 into communication with charnber 42. The pressure liquid enters the chamber 42 and turns the slide-member 40 and with it the bolt 34. Through the intermediary of the threads the bolt 34 is screwed downwards. Simultaneously the eccentric stud 36 gyrates about the axis of the bolt 34, the flrst turning movement of the bolt causing the disc I9 to move downward relative to cogging I8, and in consequence thereof the disc I9 together with the cutter 20 is cleared away from the cogging I8 of thetool spindle 4. At the same time the cutter is also cleared away in a radial direction from the work piece I, so that the return stroke of the tool can take place unimpeded by the work piece.

Now the pressure liquid is fed through the channels 43, 44 tothe chamber 4/I. The slidemember 40 and the bolt 34 are now rotate-d in the opposite direction. In consequence ,thereof the bolt 34 moves upwards, and the disc I9 is l brought into engagement with the spur-cogging I8 of the tol spindle 4, The spindle may then be further rotated, andthe cutter 20 is now in position to execute the next following Working stroke.

The Figs. 7 and 8 show a construction similar with that of Figs. 2 and 3, as also here the pressure liquid influences a piston I3 which axially displaces` the bolt I2. This bolt does not engender a tilting movement of the cutter 20 but displaces the same in the axial direction parallel to itself. The radial displacement of the cuttei` is here engendered by the piston 49 which is guided in the bore 50 into which the pressure liquid is fed through the channel 5I. The channel 5I, the bore 50 and the piston 49 are provided in the bolt 52 which is concentrically and rotatably mounted in the bolt I2.

The operation is as following: The pressure liquid is fed to the chamberA I 4 through the channel I5. The piston together with the bolt I2, the disc I9 and the cutter 29 moves downwards. Simultaneously the pressure liquid' is pressed through the channel 5I into the chamber 59. The disc and the cutter which are clear from the cogging are now radially moved -away from the work piece I by the piston 49. The upward movement of spindle 4 now takes place, with the cutter 2li clearing the work piece. In the uppermost position of the spindle the pressure liquid is fed to the chamber I'I through the channel IB, The piston I3 and the cutter move upwards, and the disc is again brought into engagement with the cogging I8 in such a way that the disc is made concentric with the axis of the tool spindle. Piston 49 is forced by disc I9 into its initial position. The cutter is now in the position to execute another Working stroke.

In the embodiment according to Figs. 9 and 10 the tool spindle 4 is mounted in the eccentric socket 10 which is arranged 'in the tool spindle carrier 54. The eccentric socket is rotated by the lever 1I. In consequence thereof the centre 12 According to the last-mentioned arrangement of the tool relatively to the work piece the masses which have to be moved are greater than in the other construction in which only the cutter is moved relative to the tool spindle. The `conl struction according to Figs. 9 and 10 can be used Y for machines with only one or with two tool spindles.

With the machines already described the teeth of the work piece are only rough-shaped during the rst full rotation of the work piece and a smoothing takes place during a second rotation of the work piece. But according tothe construction shown in Figs. 11-15 the rough-shaping and smoothing is executed during a single rotation, so that the double output is attained.

Only the described arrangement of the cutter relative to the tool spindle according to this nvention renders it possible to-provide two tool spindles, as the work piece must be moved rela.

tive to the cutter always in the line from the Acentre of the work piece to the centre of the cutter.

In the carrier 54 of the two tool spindles two sockets 55, 56 are rotatably mounted and held against axial movementat both ends. In eccen tric bores of the said sockets the tool spindles 51, 58 with the cutters 59, 66 are mounted, and l are capable of axial and rotary movements. 'I'he tool spindles are driven 'in the axial direction by a toothed sector 1 oscillating about the axis .6 and engaging annular rack teeth 5 on the spindles. l

The tool spindles are rotated by means of worms 8 and worm-wheels 5.

vWith the sockets 55, 56 levers 6I, v6l are con'- nected to which rods 63 are articulated. The levers 6 l, 62 have the purpose to adjust the direction of the clearing 'movement of the cutter rela-- tively tothe work piece, as shown in Figs. 14 and 15.

By rotation of the sockets 55 and 56 which may' be clockwise the centres 6l of the tool spindlesv The eccentric sockets 56, 56 of the tool spindles Y the centres 64 of the tools or of the tool spindles,

and it'is obvious from Figs. 14 and 15 that `the direction of the lines 66 connecting the respective centres depends from the diameter of the work piece according to which the starting position of the levers 6|l 62 has to-be adjusted.

'Ihe eccentric sockets also serve for the exact adjustment, especially in the case that after the beginning of the working the depth of. the teeth has to be more exactly adjusted within limits of- 116 millimeter for instance. For thispurpoSe the levers 6I and 62 are brought into a corresponding position which is fixed for the respective Working.

It is known that in the operations of cutting, turning and shaping with two tools on a work piece it is not possible to do the rough-working and the smoothing simultaneously. According to my invention the two tools are subjected to mutually reciprocal movements, so that the roughcutting edge is working, whilst the smooth-cutting edge is on its return and vice-versa.

For this reason the tool has during the smoothshaping a steady position in which it is not subjected to convulsions, displacements and the like. An exact and clean shaping and a longer duration of `the cutting edge is attained in this way.

What I claim and desire to secure by Letters Patent is:

1.l In combination, a spindle, a gear cogging at one end of said spindle, a ring engaging said spindle and having a. projecting lug with a ccnvex shaped end, a gear cutter havingpa cogging adapted toengage the spindle cogging and havin an annular concave shaped groove into which said convex shaped end of said lug is tted to form a hinge between said ring and said cutter.

2|. In a shaping machine, a spindle, a gear cutter actuated by said spindle, means for moving said spindle and Vcutter along `the longitudinal axis of the spindle, means for rotating the spindie and cutter about the longitudinal axis of the spindle, and hydraulic meansA disposed within said spindle for displacing said cutter relative to said spindle, said hydraulic means comprising a piston mounted within said spindle, and means securing said cutter to said piston.`

GEORG GERT IEREDERICHS. 

